Re-add ServerExternalAddresses parameter in GenerateToken endpoint
This reverts commit 5e156772f6a7fba5324eb6804ae4e93c091229a6
and adds extra functionality to support newer peering behaviors.
A previous commit introduced an internally-managed server certificate
to use for peering-related purposes.
Now the peering token has been updated to match that behavior:
- The server name matches the structure of the server cert
- The CA PEMs correspond to the Connect CA
Note that if Conect is disabled, and by extension the Connect CA, we
fall back to the previous behavior of returning the manually configured
certs and local server SNI.
Several tests were updated to use the gRPC TLS port since they enable
Connect by default. This means that the peering token will embed the
Connect CA, and the dialer will expect a TLS listener.